Chasing the 2200 rpm ping (2.7)

2000 2.7 5 speed. It's time I track down the ping that often happens between 2000 and 2500 rpm under load (when accelerating). Research shows that a dirty MAF could cause this. Is this spark knock? I cleaned the MAF this evening and will see if that helps tomorrow on the way to work.

I also noticed that I have a slight leak from the exhaust manifold. Could this leak cause the ping?

 

OK, if cleaning the MAF doesn't fix the pinging, then I just read that a cooler spark plug may be the answer. I'll pull the plugs and see what's in there. Plugs and wires were changed 30K ago(by previous owner). Maybe they installed hotter plugs. I only notice the pinging when the truck is hot.

 

I just did a head on a 2.7 that had a ping as well. We did the cooler plugs as well but turned out a hairline crack around the spark plug hole. By all means try the cheap way first.

 

Hate to hear about the crack. Were you able to repair the head?

The more I pay attention to the ping, the more I notice about it. I never even notice the sound when I'm listening to tunes. With no music on in the truck, I noticed that when truck isn't hot, there is no ping. So, it now makes since to me that a cooler plug may make the difference. Cleaning the MAF made no difference. Next step is to check my plugs and see if I can get a cooler heat range plug.

 

I had to buy a new head and the old one when we used magnetic crack locator it was a puzzle around the plug hole.
Do you have a cracked exhaust manifold?
If yes look for white stuff around the crack.
And pressure check the radiator when the truck is hot. Any see if it drops pressure head gasket or head.

 

I hate going through all the loops like that but it's how I found mine.

 

If you have an EGR system that's not working perfectly (leaking modulator or clogged passages) it can cause a ping.

 

On a supercharged motor you get the pinging real bad when the system is running too lean, I imagine that the same applies when you hear pinging on a n/a motor. Bad/old spark plugs can cause spark knock when accelerating that sounds just link pinging, so that could be it. A number of things could cause a lean condition including a dirty/bad MAF sensor, vacuum or exhaust leak somewhere, or bad O2 and/or air/fuel sensors. I'd start with the easy stuff first like replacing the spark plugs if they're due.

edit: just saw that you mentioned in your first post that you have an exhaust leak in your manifold, I bet that's the source of your pinging. Are you throwing a code? An exhaust leak should throw a lean code (P0171 or the like) I'd imagine...

 

I appreciate the input. No check engine ligh but i may ought to hook my scanner to see if any codes are lingering. Plugs and wires are only 30k old. Truck runs great otherwise.

Plan of actions:
1. pull exhaust heat shield and inspect

2. Pull plugs, inspect and log part number

3. Scan for codes

 

Scanner shows no codes.

EGR valve was replaced 40K ago.

I've been researching mini header vs LT and leading toward a mini header. I want to keep the truck quiet..

 

Like I've seen in so many other photos, here's what i founder under the shield. I plan to order the

$414 17141-75080 Exhaust Manifold

17141-75080 mini header, oem gasket, oem dual gland and oem EGR gasket. I can't seem fine find the oem EGR gasket number. Help appreciated.

 

Ok, here's the K16R-U plugs with 43k miles on them. Gaps are .038-.040". They look normal to me but I've never been a plug expert. What do you guys think..... maybe the mini header will fix the pinging? If not then try cooler plugs or something EGR related?

Something else I noticed when removing the plugs is that none of them were tight, light they were inserted hand tight and never torqued. I know it was done at the dealer(I have dealer records).

 

plugs look good. the top left one, is that oil?

 

Yep, #4 grommet must be leaking.

 

What fuel grade are you running? My 2.7 would spark knock on 87 gas around the same room range. I talked to my auto teacher at the time and he said try 89. I did, and it never happened again. I put another 100k on the engine before I swapped to a v8.

 

Best solution yet! Swap in a v8

 

I run 87 Chevron, but I tried 89 and still had ping. I did gain 1 mpg with the 89 though.

 

My 3RZ had a cracked head, cracked in four places, all around valves and plug holes. Unfortunately our valve train needs its adjustment taken around every 50-60k miles to keep from eventually doing this.

 

Wow, I hate to hear that. I was under the impression that the 3RZ was a good,reliable and easy to maintain motor when I bought this truck.

 

It is, but the issue is people take that to mean they don't have to do preventative maintenance. When that happens it usually bones the next dude to own it. If you keep up on the valve clearance checking and adjusting and you give it regular oil changes it'll be good to you. Mine still runs like a beast after its new head. Anyone will tell you I am not easy on it either, but I do all of my maintenance like my life depends on it.